1. Field of the Invention
The present invention relates to a method for cleaning birds which have been soiled by various products, and notably by hydrocarbons, as well as to a cage for cleaning the birds and to devices for implementing the method and employing the cage.
The invention finds useful application in ornithological stations or in places where pollution has occurred.
2. Prior Art
The cleaning method most frequently employed is described in an article by G. Bents published in issue 15 of "L'oiseau magazine" (1989) and consists in manually washing birds that have been victims of pollution by hydrocarbons using a mixture of hot water and detergent and then washing them with ordinary clean water. This delicate method should only be used by ornithologists. The time needed to clean one bird is between 25 and 60 minutes.
An automatic apparatus for removing pollution from birds is described in French Patent 2,638,319. The apparatus consists of two tanks arranged on different levels the upper tank being provided with means for delivering fixed jets of water oriented respectively downwards at the upper part, sideways at the middle part and vertically at the lower part. The means for delivering the jet of water comprise a wavy pattern of perforated tubes situated in the upper tank, or a double-walled upper tank with perforations on the inner side. The base of the upper tank is perforated to allow water to flow to the lower tank. In the latter, a pump is provided for supplying the jets of the upper tank. The upper tank is covered by a ventilated cover allowing air to be circulated. The bird to be cleaned is placed in the upper tank and subjected to the action of the fixed water jets, including the bird's head.
Between a cleaning and a rinsing operation, the lower tank is manually separated from the upper tank. This apparatus suffers from the following disadvantages:
- there is no provision for keeping the bird in place which means the bird will probably make unexpected movements and get injured during washing, or the bird will tend to lie down with its wings folded, thus making it impossible to clean under the bird's wings. Moreover, in the absence of any system for restraining the bird, it is difficult to recapture the bird in the tank after cleaning, the danger of escape and injury being always present. It is thus extremely difficult to ensure cleaning is done properly.
- the bird's head is in the cleaning zone. When a tired bird is washed for a long period, there is a real danger of drowning.
- recycling of the dirty water by the pump leads to the clean area of plumage becoming polluted, and extends the duration of cleaning. Moreover, the clean water used for rinsing is always polluted by hydrocarbon traces in the lower tank, on the pump and in the piping. It has however been established that effective rinsing requires all hydrocarbon traces to be removed from the bird's plumage.
- the water injection system ("holes" in a coiled pipe) or a double wall is not sufficient to produce jets that are powerful enough to remove patches of hydrocarbon.
- the temperature of the circulated water decreases very rapidly. However, a high temperature is necessary in order to insure good quality cleaning and to keep the bird in a good general state.
- the need to frequently change the water in the lower tank due to its becoming polluted and cooling down rapidly goes against a need to reduce staffing costs and could lead to the pump being damaged or the complete system failing.
- the size of the upper tank needs to be adapted to the size of the bird requiring cleaning. It is consequently necessary to provide a whole set of tanks for treating birds of different sizes.
- in view of the mediocre quality of the cleaning achieved, the birds' plumage is not made impermeable, and the device can only be used for cleaning birds of the anatidae species, such as wild ducks or mallards, which live temporarily in water and always provided that the soiling of the feathers is the result of the water being polluted by relatively light hydrocarbon such as domestic heating oil or gas oil. The device is not suitable for dealing with pollution from heavy hydrocarbons such as heavy oils and crude petroleum. For birds of the alcidae species (such as guillemots and small penguins) which live permanently on water, their plumage must be cleaned perfectly in order to be impermeable and this cannot be obtained with the prior art device.
U.S. Pat. No. 5,009,197 discloses a method for removing oils from birds and animals. In the method, the bird is successively dipped manually into various tanks containing cleaning fluids agitated by jets supplied by recirculation pumps.
To overcome the difficulties of keeping the creatures in the tank, they are placed in an open mesh cage which leaves them free to move inside the cage. Cleaning of the head and the upper part of the body of the animals is done manually by means of a jet supplied by a cleaning liquid pump.
The method does not enable those parts of the bird that are masked by its wings to be cleaned and requires numerous and delicate manual operation to be carried out. Moreover, a set of different sized cages is needed adapted to the size to the animals to be treated.